Electric switch



P. P. QUAYLE ELECTRIC SWITCH April 1, 1930.

Filed June 14, 1927 2 Sheets-Sheet l P. P. QUAYLE ELECTRIC- SWITCH April 1, 1930.

Filed June 14, 1927 2 Sheets-Sheet 2 Patented Apr. 1, 1930 UNITED STATES PATENT OFFICE ELECT-RIG SWITCH Application filed June 14, 19 27. Serial. No. 188,862.

This invention relates to switches and has for its object to provide a construction more simple and positive in operation, as well as more-etficient in use, than those heretofore proposed.

With these and other objects in view the invention consists in the novel details oicon- 'struction and arrangements of parts as will be more fully hereinafter disclosed and particular'ly pointed out in the claims.

Referring to the accompanying drawings forming a part of this specification in which like numerals designate like parts in all the views;

Figure 1 is a top plan view of the switch;

Figure 2 is a side elevational view of the parts illustrated in Figure 1;

Figure 3 is a detailed illustration of the spring mechanism used in connection with the switch;

Figure 4 is a sectional view taken as on the line 4-4 of Figure 3 and looking in the direction of the arrows;

Figure 5 is a sectional view taken as on the line 55 of Figure 3 and looking in the direction of'the arrows; and

Figure 6 is a sectional view taken as on the line 66 of Figure 2 and looking in the direction of the arrows.

This invention has utility wherever the instantaneous flow of an electric current is desired, and has proved itself extremely valuable in the control of a sparkconstitutin the source of light in connection with the ta ing of photographs, or shadowgraphs, or silhouette pictures of swiftl moving objects including bullets and the li e, the image being formed on a sensitive surface which may be developed by treatment I with suitable chemicals whereby a permanent pictorial record may be obtained. In the investigation of real speed phenomena wherein a moving object appears stationary, a spark controlled as by the invention presently to be described is of great value due to-its short duration.

Two distinct problems are presented in the photography of moving objects. One of these is the timing of the spark so that the desired epoch of the phenomenon under inelectricity at very rated from a companion and similar met be photographed, and the other has to o with the duration of the spark. A projectile movingat a speed of 2,700 feet per second would be in front of such a plate, and, therefore, in a position to be photogra hed for only 0.0003 second. If the projecti e is to be photographed within an inch of a predetermined position, the time of occurrence of the spark must be correlated with the position of the projectile to within 0.00006 second.

The spark duration determines the amount of blurring, for if the projectile moves while the plate is being illuminated a streak will be recorded, the length of which deppnds on the duration of this spark. If the lurringv is not to extend over more than one-sixteenth of an inch for a projectile moving at a speed of-2,700 feet per second, the time ofex'posure must not exceed two-millionthsof a second.

In order to secure a properly timed spark of suitable character there must be available a means of generating electrical energy at very high voltage, a means of storing such energy, apparatus for the regulation of the voltage a'nd, finally, a means of releasing the stored energy at the proper time. This investigation ma 'vention has to do with the. release of said energy only. B0

The charging circuit could be any suitable circuit including a condenser having a charge receivin surface upon which a high potential couldie built, from a generator of high volta 'e which may be either a static machine, '-ray tube and transformer, or equivalent means. The apparatus for regulating the voltage of the con- I denser could include -a dynamometer, or potential-limiter, and a switch which disconnects the condenser from'the generator or other influence machine when the voltage across its terminals reaches a definite value predetermined by the potential-limiter adjus't-ment. e

The discharging circuit'should include the condenser from one side of which a conductor 51 leadsto a metallic terminal 52 se 1:;-

0 terminal 53 by a substantial air gap, and :1

conductor 55 leadin from the terminal 53 back to the other si e of the condenser with the spark gap interposed in said conductor 55. A damping resistance, seriall connected between the spark gap and t e condenser is provided to damp the discharge circuit to obtain a single flash of the shortest possible duration for the particular circuit in question. If the circuit is permitted to oscillate the condenser produces a series of sparks and therefore a series of images of progressively diminishin intensity. Since a given potential is capafile of jumping a definite gap the circuit is so arranged that the condenser cannot discharge through both the air orterzninal gap and the spark gap, but if the former is closed then the condenser discharges through the latter with which it is in series.

The spark switch comprises an aluminum arm 60 rigidly carryingat its end a cross bar 61 of a length just slightly less than the air gap between the spark switch terminals 52 and'53, and. adapted to pass through said gap when the arm 60 is rotated about the shaft 62 passing through its other end. That is to say, one extremity of said arm is rigidly secured to the shaft 62 supported in split bearings 63 and 64 disposed on either side of said arm, the shaft 62 being of suficient length to extend a slight distance beyond the outer sides of said bearings. To one end of the shaft 62 is rigidly secured a spring 65, the free end of which carries a circular hearing collar 66 into which is adapted to fit a pin 67 carried at the end of a crank 68 rigid 1y secured to the inner end of a stub shaft 69 adapted to be clamped in a split journal sup port 70. Near the outer end of this stub shaft: and in close contact with the journal sup= port 70 is rigidly mounted an enlarged collar 71 tapped to receive a set screw 72 adapted to pass through an arcuate opening 73 in a collar 7 4 adapted to freely encompass the collar 71. The periphery of the collar 74 carries suitable scale markings 75 adapted to coact with an index line 76 provided on the upper surface of the cap portion ofthe journal support 70. Through the extrgmity gf the shaft 69 is tightly driven a rod as a handle by which the stub shaftigii) may be adjusted. A spring 80 is similarl fgmounted on the opposite end of the shaft -62and is similarly connected to a crank 81 which-is a duplicate of the crank 68, and thecrank 81 is mounted on the inner end of a stub shaft 82 which is a duplicate of the stub shaft 69.

The purpose of having the two independent stub shafts 69 and 82 in coaxial alignment with the shaft 62 is to take care of inequalities that may exist between the springs and 80, so that equal tension may be placed upon the shaft 62 whereby the aluminum arm 60 carrying the cross bar 61 may move in a substantially true vertical plane when said shaft 62 is rotated. The arcuate openings are provided in the encompassing collars 74 and 84 so that the same registrations may be obtained between the scale markings of said collars and the indices associated therewith. When the arm 60 is under substantially no tension, the collars.74 and 84 are positioned by the set screws 72 and 86 to give a zero reading on the scale markings and the arm 60 is then moved to rotate its shaft 62 against the tension of the springs 65 and 80 until the free end of the arm 60 has been moved into locking engagement with the holding catch 90, see Figure 2. The arm then being under considerable tension it will, when the latch 90 is loosened, fiy back through the same are that it moved through during the latching operation, and in this movement it will carry the cross bar 61 through such a path that the axis of said cross bar will intercept the common axial line passing through the switch terminals 52 and 53, see Figure 6. VJ hen this occurs the air gap will be bridged whereupon the potential charge in the condenser will be released, creating the desired spark at the spark gap. To prevent undue movement of the cross bar arm 60, there is provided a buffer 93 which maybe strands of rubber or other yieldable material held by two supporting posts 94 and 95 in such spaced relation with respect to the plane of movement of the arm 60, that said arm will strike said buffer and come to rest thereon in the dotted line position shown in Figure 5.

It is found highly desirable to use a crossbar movable between two stationary terminals such as 52 and 53 as by doing so the gap between the terminals is closed twice as fastas a gap using one terminal only. That is j to say, if the arm 60 was connected in the discharge circuit as one switch terminal in. place of 52 and adapted to swipe? or brush past the terminal 53 then the gap therebetween would necessarily have to be increased to avoid a jump thereacross of the high potential charge. Thus it is obvious that with the same angular speed of the arm 60, and the construction herein employed, the total length of the gap required to prevent the passage of the charge isdivided in half as a result of which the arm 60 need travel only half the distance, to permit the discharge, that it would have to travel using no crossbar and only one stationary ter1ninal. Therefore, by this improved construction, the actual discharge israccomplished more nearly simultaneous with the release of iii the arm, especially so in view of the fact that the tenslon used at present on the springs 65 and 80 can be readily adjusted through a ran e extending from a minimum of 0.0048 secon to 0.1 second or more, and that said minimum could be still further reduced by stifiening said springs. It mi ht here be stated that in general the total tlme interval ela sing between the release of the arm 60 an the occurrence of the photographing s ark is not as im ortant as the regularity 0 performance of t e apparatus. The variation of the resent switch seldom exceeds 0.00001 secon and is usually very much less.

The supports 63, 64, 70 and 88 are mounted on a suitable plate 97 of non-conducting material which is in turn supported by nonconducting posts 98 from a ed plate 99 likewise of insulating material so that there is provided a substantial air space between the plates 97 and 99. Also mounted on the plate 97 are non-conducting posts 100 and 101 through the upper portion of each of which is slidably disposed the metallic rods 102 and 103 carrying at their innermost extremities the switch terminals 52 and 53 respectively. In the outer extremities of the rods 102 and 103 are transverse bores 104 and 105 adapted to receive the ends of the conductors 51 and 55 which are respectively and rigidly held by set screws 106 and 107. The rods 102 and 103 are slidingly positioned in their sup rting posts so that the terminals, 52 an 53 carried by said rods are not quite touched when the cross bar 61 is moved therebetween by the switch arm 60, and said rods 102 and 103 are then clamped in said position by setscrews 108 and 109 disposed in the upper extremit of the su ortin osts all as will be clear from Figli e 6. g p

The circuit controlling the release of the discharge and hereinafter referred to as the seconda or control circuit in contradistinction to t e primary or charging circuit includes an interrupter which is a device controlled by the n or 0 erated when the gun is fired. In 0t er wor s, it is a device placed in the control circuit and affected by the firing of the gun to cause an electrical change in said circuit. The device may be of any convenient form although it is preferable when this apparatus is used in connection with photographing bullets at some distance from the gun to employ an interrupter pro- Vided with a diaphragm adapted to be actuated by a sound wave. That is to say, an interrupter is employed which will momentarily breakthe control circuit, said interrupter being connected on one side thereof bya conductor to one side of a battery or source of current, the other side of said battery being connected as by the conductor 118 to a coil 119 provided 'with an iron core which will be mafipetized by the current from the battery. e coil 119 is connected on its other side b the conductor 120 with the other side 0 the interrupter. Thus it will be seen that when the circuit is closed through the interrupter, the coil 119 will cause the magnetization of its core which in turn will attract and hold in contact therewith the armature 121 which is connected with the latch 90, and when the interrupter is disturbed, the electric circuit will be broken therethrough whereupon the core of the coil 119 will be demagnetized, allowing the armature 121 to move out of contact with said core by virtue of the spring 122, which is also instrumental in moving the latch 90 to release the end of the switch arm 60 so that it may move about its pivot shaft 62 and cause the cross bar 61 to bridge the air gap between the switch terminals 52 and 53. I If desired a suitable resistance may be thrown into the change circuit.

Figures 1 and 2 clearly disclose the apparatus for releasing the switch arm 60 wherein it will be seen that the plate 97 is provided with guide plates 130 and 131 in which is adapted to be slidingly positioned the base member 132 on which is rigidly mounted a frame 133 carrying a pair of coils 119 and 119*. The frame 133 may suitably support these coils b having the cores 134 and 135 thereof rigi ly secured to a portion of said frame. The coils are separated to permit the passage therebetween of a rod 136 of highly insulating material one end of which is pivotally secured as at 137 to the holding latch 90 pivotally supported as at 138 to the base 132. The other end of the rod 136 rigidly carries the armature 121 which has an extension 140 pivotally secured to one end of a link 141 pivotally secured atits other extremity to the frame 133 carrying the coils. The spring 122 is secured to an extension of the link 141 and said spring preferably is disposed in the same vertical plane with the latch actuating rod 136 and the switch arm 60, and is in coaxial alignment with said-rod. The other end of the spring is secured to the end of a screw 145 provided with a longitudinally extending slot 146 adapted to receive a pin 147 carried by a bracket 148 rigidly secured to the, base 132. The screw 145 freely passes throu h the bracket 148 and has mounted on its 0t er extremity a knurled thumb nut 149 adapted to enga e the flat surface of the bracket 148. By t e above mentioned construction, and with particular reference to Figure 2, it will thus be seen that the spring 122 can be placed under varying tension by means of the screw 145 and the nut 149 associated therewith, the pin 147 preventing a turning movement of said screw. Thus the spring 122 performs the function of accelerating the movement of the armature 121 away from the demagnetized cores of the coil 1 19 when the secondary circuit is broken through the interrupter, and further insures a quick and immediate release of the switch arm 60 fromthe holding latch 90.

It may be necessary under varying cond1- tions of temperatures and wear to a just the position of the latch 90, and to permit of such adjustment the plate 97 has rigidly secured thereto an upstanding lug 155 in which is mounted a collared screw 156 the extremity of which is threaded into the vertical portion of the bracket 148 which is rigidly carried by the base 132 carrying the coils 119 and 119. To the other end of the screw 156 is rigidly secured a knurled nut 157 by means of which the screw may be actuated to cause a sliding movement of the base 132 in the guides 130 I and 131 provided therefor. By such a construction the base 132 may be so moved as to ause the latch 90 to engage the switch arm 60 only an amount sufficient to hold the same, so that when the interrupter functions, the said latch will substantially simultaneously release said arm.

In the operation of the device for the purpose of obtaining a picture of a bullet in transit, the operator sets or cocks the switch arm 60, and places the interrupter a short distance away from the trajectory of the bullet and a sufficient distance from the photographic film to allow for the time lag in the apparatus.

This may be accomplished either by trial or by determining the lag of the switch experimentally and by a simple computation based on the value of the lag and the approximate speed of the shot or bullet find the proper position for the sound wave interrupter. The apparatus of course is placed in a dark room with the sensitive film facing the spark ga and then the influence machine is started to uild the voltage across the condenser up to the point at which the potential-limiter functions. lVhen this occurs e'the influence machine is short circuited thus preventing the accumulation of further charge on the condenser and at the same time a signal is produced for the firing of the gun.

The bullet then leaves the muzzle of the gun, passing the interrupter and as the accompanying sound wave passes the interrupter the circuit is opened through the coil 119, de-energizing the magnetic core thereof, and the armature and holding latch are released. The switch arm with its cross bar then closes the gap between the terminals 52 and 53 and the condenser discharges through said cross bar and gap as well as the spark gap with which it is in series. If the interrupter has been properly located, the spark occurs at the instant the bullet arrives in the desired position between the spark and the sensitized film to produce the record thereon.

Special care is taken in mounting the entire apparatus, use being had of dust-proof housings, electric ruby lamps for safe light and heat for drying any moisture present, pyrex tubing for insulatingly encasing the wlring,

and corners etc. of the apparatus being carefully rounded to reduce the density of charge and conseguently the leakage of said charge which is o the order of 200,000 volts.

It is obvious that those skilled in the art may vary the details of construction and arrangements of parts without departing from the spirit of the invention, and therefore itis not desired to be limited to the foregoing dis closure except as may he demanded by the claims.

What is claimed is 1. A switch comprising a shaft, an arm carried by said shaft, a terminal interposed in a circuit and adapted to be electrically engaged by said arm, balanced springs cou led to the ends of said shaft, and a latch to old said arm under the tension of said springs.

2. A switch comprising a shaft, an arm carried by said shaft, a terminal interposed in a circuit and adapted to be electrically engaged by said arm, springs coupled to the ends of said shaft, means for creating equal tension on said springs, and a latch to hold said arm under the tension of said springs.

3. A switch comprising a shaft, an arm carried by said shaft, a terminal interposed in a circuit and adapted to be electrically engaged by said arm, springs coupled to the ends of said shaft, means including adjustable cranks for creating equal tension on said springs, and a latch to hold said arm under the tension of said springs.

4. A switch comprising a shaft, an arm carried by said shaft, :1 terminal interposed in a circuit and adapted to be electrically engaged by said arm, balanced springs coupled to the ends of said shaft, a latch engaging said arm under the tension of said springs at one limit of its movement, and resilient means engaging said arm at the other limit of its movement.

5. A switch comprising a shaft, an arm carried by said shaft, a terminal interposed in a circuit and adapted to be electrically engaged by said arm, balanced springs coupled .to the ends of said shaft, and a latch responsive to electrical influence for controlling said arm.

6. A switch comprising a shaft, an arm carried by said shaft, a terminal interposed in a circuit and adapted to be electrically engaged by said arm, balanced springs coupled to the ends of said shaft, and a latch bodily movable with respect to said arm to hold the latter under the tension of said springs.

7. A switch comprising a shaft, an arm car ried by said shaft, a terminal interposed in a circuit and adapted to be electrically engaged by said arm, balanced springs coupled to the ends of said shaft, and a latch slidably adj ust able to hold said arm under the tension of said springs.

8. A switch comprising a shaft, an arm carried by said shaft, a terminal interposed in a circuit and adapted to be electrically enga db said am balanced s rings cou led tofiie slide of saidshaft, and piyoted atch susceptibIe of slidable adjustment with respect to said arm to hold said arm under the tension of said springs.

9. A switch comgrising a shaft, spaced bearin s for said s aft, an arm carried by said aft intermediate said bea a crosshead on said arm, a air of termina interposed in a circuit an adapted to be electrically engaged b said crosshead when assing therebetween, alanced springs cou ed to the ends of said shaft, and a latch to ho (1 said arm under the tension of said sprin In testimony whereof I aflix m 81 ature.

PHILIP POLLOCK Q A E. 

